Possible memory leak in DelegatingHandler?

I and my colleague have discovered a potential memory leak in the DelegatingHandler. During the performance testing of the services we are developing we found out that the memory consumption of the W3WP.exe-process
hosting our services was constantly increasing for every request. After investigating this for a while we found out that the problem was related to our custom DelegatingHandler, since the memory consumption was stable after we removed our DelegatingHandler.
We decided to take a memory dump and found out that the top 5 types in the heap were the following:

The DelegatingHandler method SendAsync takes a CancellationToken, and without digging deeper in the Web Api framework we can see a link between the CancellationToken and the findings in the heap.

In order to eliminate the possibility that our own code was causing any problem we made a simple application with just one simple resource that has a GET operation. We also created a custom ServiceHostFactory
and a custom DelegatingHandler:

I and my colleague have discovered a potential memory leak in the DelegatingHandler. During the performance testing of the services we are developing we found out that the memory consumption of the W3WP.exe-process
hosting our services was constantly increasing for every request. After investigating this for a while we found out that the problem was related to our custom DelegatingHandler, since the memory consumption was stable after we removed our DelegatingHandler.
We decided to take a memory dump and found out that the top 5 types in the heap were the following:

The DelegatingHandler method SendAsync takes a CancellationToken, and without digging deeper in the Web Api framework we can see a link between the CancellationToken and the findings in the heap.

In order to eliminate the possibility that our own code was causing any problem we made a simple application with just one simple resource that has a GET operation. We also created a custom ServiceHostFactory
and a custom DelegatingHandler: